c[10];d[10];f(int*a,int*b){return*a-*b;}unsigned long s;main(a,b,n,i,v){for(gets(&n);~scanf("%d%d%d",&a,&b,&n);printf("%.6lf\n",1.*s/(n-a-b))){memset(c,0,40);memset(d,15,40);for(s=0,i=n;i--;s+=v){scanf("%d",&v);*c=*c>v?*c:v;d[9]=d[9]<v?d[9]:v;qsort(c,10,4,f);qsort(d,10,4,f);}for(i=9;i>(9-a);)s-=c[i--];for(i=0;i<b;)s-=d[i++];}}
